Apron tuyere for stokers



' Jan. 1s, 193s.4 R. L. BEERS 2,105,875

APRoN TUYERE FOR sToKERs Filed Oct. 7, 1935 2 Sheets-Sheet -2 VENTOR ROYCE L. RS

BY l k @mum Patented Jan. 1.8, 1938 UNITED STATES APRON TUYRE Fon, STOKERS Royce L. Beers, Birmingham, Mich., assigner to Detroit Stoker Company, Monroe, Mich., a corporation of Michigan Application October 7,

13` Claims.

This invention relates to stoker constructions of the sprinkler type in which mixed ne and coarse fuel is thrown into the furnace chamber over the grate. With this type of construction,

there is a tendency for the ne fuel, and particularly the dust, to drop down adjacent to the front wall of the furnace where it will accumulate without being fully burned. To avoid such an effect furnaces have been provided with apron tuyres which project rearward and incline downward from the front wall and have air discharge openings at the rear end thereof. With such a construction, the fine fuel and dust falling upon the inclined apron will travel down the same, meeting the air at the lower rear end, and being blown rearward therefrom.

The present invention relates to apron tuyres of the type just described and has for its object the obtaining of a construction formed in units which can be easily installed and quickly removed at any time for repair or replacement.

It is a further object to provide effective means for protecting the tuyre from the furnace heat so as to prevent burning out of the same.

With these objects in view, the invention consists in the construction as hereinafter set forth in the drawings:

Figure 1 is a vertical section through a portion of the front wall of the furnace below the fuel feed opening therein showing my improved open tuyre applied thereto;

Figure 2 is an elevation viewed from the right of Figure 1 showing the manner of mounting and securing a series of tuyres across the furnace chamber;

Figure 3 is a perspective view of one of the tuyre sections removed;

Figure 4 is a similar View showing the heat insulating unit for the tuyre.

As shown in Figure 1, the furnace has a front wall A with a fuel opening B therein, in front of which is the stoking and sprinkling mechanism (not shown). C is a replaceable wear member which forms the bottom of the fuel opening and which has a hooked engagement with a member D on the furnace wall. E is a member secured adjacent to the inner face of the furnace wall and provided with an upwardly extending hook F for supporting the apron tuyre members. The members E and F extend completely across the furnace chamber to the side walls G and G1 thereof.

The apron tuyre units are of the construction shown in Figure 3, being provided with a downwardly and rearwardly inclined apron portion H 1935, Serial N0. 43,949

and a downwardly and forwardly inclined returnportion I. The portion H is provided on its underside with a hook J for engaging the hook F and thereby retaining the unit upon the furnace wall. The hook J is in the central portion of the apron H and merges into a rib J1 extending downwardly on the inner side of said apron. On opposite sides of thev lower portion of this rib are the wings J2 and J3 which extend for the full width of the apron H, and forming between the same and the apron air channels J4 with outwardly opening ports J5 near the bottom of the apron. The portion I is of a channel-shaped cross section having the downwardly extending sides I1 and the inwardly extending flanges I2. This channel is open at the inner end and inclines downward towards the forward end which is closed by the portion I3 bearing against the member E. Thus, when the unit is mounted with its hook J engaging the hook F, it will form in connection with the member E, a triangular shaped member.

In installing these tuyre units, they are successively placed in position with the hooks J engaging the member F which forms a rail extending completely across the front wall of the furnace chamber. The units can then be slid upon this rail into proper position with the adjacent units abutting against each other. To form a better seal between these units the opposite edges of the apron H are fashioned to form a break joint, being provided on one edge with the proj ecting tongue portion H1 and upon the opposite edge with a groove or rabbet H2 for engaging the tongue of the adjacent unit. These tongues and grooves are engaged by laterally sliding the unit upon the rail F. However, at the ends of the series it is necessary to provide closing members for forming tight joints with the side walls G and G1. This is accomplished by a member K which is similar in form to the apron unit but of lesser width. On one side of this unit is a groove K1 corresponding to the grooves H2 and adapted to receive the tongue H1 of the adjacent unit, while the opposite side of the member K is plain to bear against the furnace wall. Thus, in installing the units one member K is first placed adjacent to one wall of the furnace chamber, the apron units are then successively installed and slid laterally to engage the tongues H1 with the grooves H2, and finally` at the opposite ends of the series a second member K is inserted. This is arranged with its plain side against the tongue side of the adjacent unit and its grooved side against the furnace wall, thus requiring no lateral movement and completely filling the space between the last unit and the wall. A lug J 6 projects from one side of each unit and engages a corresponding recess at the opposite side of the adjacent unit.

Air is supplied to the chamber within the units through a suitable conduit (not shown) at one or both ends of the series. From the chamber, air passes outward through the channels J4 and ports J 5 1blowing the dust Yand fine fuel rearwardly and assisting in supporting combustion. This constant discharge of air will keep the apron portion of the tuyre suiciently cool, but the lower portion I requires rprotection against the intense furnace heat. This is accomplished by providing a series of heat ,insulating units L, preferably formed of rebrick, and so fashioned as to slidably engage the channel portions I and to completely protect the same. As shown in Figure 4, the member L .has a lower portion L1 which is of the fullwidth of the member I and an upper portion L2 of less width which ts'within `the channel and has the under-.out grooves L3 for Aengaging the anges I2. This permits of slidably engaging the members L with the apron units after .the latter have been mounted-in position within-the furnace chamber. When thus installed, the units L will abut against each other, each having a front portion L4 for covering the rear ends of the members I, while the portion :Ll -extends 'beneath the member Iand protects the same.

My improved apron tuyre `constructed as above described, is particularly adapted for quick installation in the furnace and also for the replacement of any `unit which may have become damaged. The forming of the heat protecting units L as separate and distinct from the tuyre units 4is advantageous, as .these may become damaged and without anyinjury to the tuyre and can be #easily replaced. Also, -by .form- -ing these protecting units of material such as rebrick they can be made of greater 4thickness and have greater inherent strength than any insulation formed from plastic material applied directly to the metal. To furtherprotect .the units, air chan-nels are formed adjacent to the engaging portions of the metal and of 4the insulating member, these being connected to the air supply through a port I4 formed'in the member I. This permits a flow of air through said port around the clearance space between the portion :L2 and the channel member I, and particularly along the grooves L3 adjacent to the iianges I?. As a consequence, the metal -is held at a sufficiently low temperature to retainits rigidity and'to prevent burning out.

Another advantageous feature is the break joint engagement between the `successive ytuyre units. This-not only prevents .escapeof air where it is not desired, but'also prevents thexdust from the fuel -passing through Athe crevice and filling -up the tuyre.

lWhat I claim as my invention is: f

1. In a furnace, the combination with a `furnace wall, of an apron tuyre detachably engaging said wall and projecting into the vfurnace chamber, said unit comprising an apron portion extending rearward `and downward from said wall, a return-portion extending forward to said wall and.' together ltherewithand said apron portion forming an air chamber with portsl `opening ltherefrom through the zlower end vof said apron, and a heat insulating unit detachably engaging said return-portion and covering the same.

2. In a furnace, the combination with a fur-r nace wall, of an apron tuyre detachably engaging said wall and projecting into the furnace chamber, said unit comprising an apron portion extending rearward and downward from said wall, a return-portion extending forward to said wall and together therewith and said apron portion forming an air chamber with ports opening 4therefrom through the lower end of said apron, and a heat insulating unit slidably engaging said return-portion from the rear end thereof and covering the rear end and bottom thereof.

3. In a furnace, the combination with a furnace wall, of an apron tuyre detachably engaging said wall and projecting into the furnace chamber, said unit comprising an apron portion :extending rearward and downward from said wall,a return-portion extending forward and inclining downward to said wall forming in con- -nection therewith and said apron an air chamber having ports 4opening through the lower .end 4of said apron, ,and a heat insulating .unit slidably engaging said return-portion from the rear end thereof and covering said rear end and bottom whereby said insulating unit will. be held in postion by gravity.

4. In a furnace, the combination with a furnace wall, of -an apron tuyre detachablyengag.- ing said wall and projecting into .the furnace chamber, said 4unit comprising an apron portion extending reaward and downward from said wall, a return-portion Yextending forward and inclining downward to .said wall being of `a channelshaped cross section open at the rear end, .andI a heat insulating unit having a portion slidably engaging said channel and having portions covering the rear end and bottom thereof.

5. In a furnace, the combination with a furnace wall, of an apron tuyre detachably .engaging said wall and projecting into the furnace chamber, said unit ,comprising .an apron portion extending rearward and downward from said wall, a return-portion extending forward Ito said -wall and together therewith and said apron portion forming an air chamber with .ports opening therefrom through the lower end lof said apron, Va heat insulating .unit detachably engaging 1said return-portion and -covering the same,

and means for owing air from said c hamben, adjacent to the engaging portions of said returnportion and heat insulating .unit t0 lower Ythe temperature thereof.

6. In a furnace, the ,combination with ,a furnace wall, of an apron tuyre detachably .engaging said wall ,and projecting into the furnace chamber, said unit comprising an `apron lportion rext-.ending rearward and downward from said wall, a return-portion extending forward land inclining downward `to said wall beingof la channel-shaped cross section open at the Yrear end. a heat `insulating unit having .a portion slidably engaging saidchannel and having ypoltiolllicovering the rear end and bottom thereof, and means for feeding air from said chamber through said channel to lower the temperature tof the metal in engagement with said 'heat insulating unit.

:turn-portion extending forward to said wall and l5 together therewith and said apron portion forming an air chamber witn ports opening through the lower end of said apron portion, said units having their edges fashioned to form a break joint therebetween.

8. In a furnace, the combination with a furnace wall, of an apron tuyre detachably engaging said wall and projecting into the furnace chamber, said tuyre being formed of a series of units, each having an apron portion inclining rearward and downward from said wall, a return-portion extending forward to said wall and together therewith and said apron portion forming an air chamber with ports opening through the lower end of said apron portion, the apron portions of said units being formed with a projecting tongue on one side and a groove on the opposite side whereby one unit may be moved laterally into engagement with an adjacent unit to form a break joint therebetween.

9. In a furnace, the combination with a furnace wall, of an apron tuyre detachably engaging said wall and projecting into the furnace chamber, said tuyre being formed of a series of units, each having an apron portion inclining rearward and downward from said wall, a return-portion extending forward to said Wall and together therewith and said apron portion forming an air chamber with ports opening through the lower end of said apron portion, the apron portions of said units being formed with a projecting tongue on one side and a groove on the opposite side whereby one unit may be moved laterally into engagement with an adjacent unit to form a break joint therebetween, and a filler at the end of the series for closing the gap between the last unit and the furnace side wall.

10. An apron tuyre unit for attachment to furnace walls comprising an apron portion inclining rearward and downward from the wall, a rib arranged centrally on the underside of said apron portion for reinforcing the same,y wings projecting laterally from the opposite sides of the rearward portion of said rib and extending beneath the end oi the apron portion to leave open ports therebetween, a hook at the upper forward end of said apron portion for attachment to the furnace Wall, and a portion inclining downward and forward from the rear end of said wings to said furnace wall and forming in connection therewith and said apron an air chamber.

1l. An apron tuyre unit for attachment to furnace walls comprising an apron portion inclining rearward and downward from the wall, a rib arranged centrally on the underside of said apron portion for reinforcing the same, wings projecting laterally from the opposite sides of the rearward portion of said rib and extending beneath the end of the apron portion to leave open ports therebetween, a hook at the upper forward end of said apron portion fo'r attachment to the furnace wall, a portion inclining downward and forward from the rear end of said wings to said furnace wall and forming in connection therewith and said apron an air chamber, and means on said downward and forward inclined portion for detachably engaging therewith and securing thereto a heat insulating block.

12. An apron tuyre unit for attachment to furnace walls comprising an apron portion inclining rearward and downward from the wall, a rib arranged centrally on the underside of said apron portion for reinforcing the same, wings projecting laterally from the opposite sides of the rearward portion of said rib and extending beneath the end of the apron portion to leave open ports therebetween, a hook at the upper forward end of said apron portion for attachment to the furnace wall, a portion inclining downward and forward from the rear end of said wings tov said furnace wall and forming in connection therewith and said apron an air chamber, and a channel-shaped downward extension on said downward and forwardly extending portion constituting a means for attaching a heat insulating block thereto.

13. An apron tuyre unit for attachment to furnace walls 'comprising an apron portion inclining rearward and downward from said wall, a return-portion extending downward and forward to said wall and together with said apron portion forming an air chamber, a tongue projecting from one edge of said apron portion and the opposite edge being provided with a groove whereby a series of said units will form break joints therebetween thereby preventing the sifting of ne fuel into the tuyre to clog the same.

ROYCE L. BEERS. 

